Aerial Movement

Aerial Movement

Moving through the air can be more complex than simply walking across the ground, especially if you’re in an airship. Like the larger flying creatures, airships have some restrictions on the rate at which they can turn and their ability to rise or descend. These limits are based on the maneuverability of the vessel and its speed, as well as the skill of the captain and crew.

Aerial Movement Scales and Rates

As with standard movement, there are three scales used when handling aerial travel: tactical, local, and overland. Though each of these movement scales are handled the same, they offer varying degrees of precision and each is best suited for use in particular types of situations.

Tactical Movement

This type of movement deals in six second rounds and allows for the most accurate tracking of airship placement and movement. Because airships move much more quickly than do most creatures, movement is handled in 50 ft. increments at this scale, rather than the 5’ increments most often used when tracking the movement of creatures or characters. This movement scale should be restricted to use in combat encounters or where the precise positioning of an airship is important (such as when a ship is moving through a particularly treacherous canyon or mountain pass, for example).

In general, this movement scale is best handled through the use of miniatures (or counters of the appropriate size and shape) and a combat map. This allows everyone to visualize the scene more easily and helps organize and coordinate movement of various vessels.

When engaged in tactical movement, vessels may move at any speed up to their full movement rate, with the standard restrictions for turning, accelerating, rising, or descending (see below).

Local Movement

At this scale, movement is handled in one-minute increments. A vessel may move up to ten times its standard tactical movement rate while engaging in local movement and the captain only needs to make a Piloting check if it attempts to turn more than ten times during each minute or if it passes through a square containing an obstacle of some sort. Local movement is best used to represent scouting missions, or instances when the airship is moving through an area in search of something specific. It can also be used effectively if the details of movement are somewhat important, such as when an airship attempts to navigate between mountains or in cases where foul weather endangers the ship.

Overland Movement

When a vessel is flying from one point to another, it is rarely necessary to map out each step of the journey, or to play through every minute of travel. In general, overland movement is measured in hours, though some GMs may prefer to use days if they have no plans for encounters to occur during the journey.

Aerial Movement Basics

Airships do not move in the same way as characters or creatures. In this section, various aspects of aerial movement are discussed, including information for determining the speed at which an airship can rise or descend and how airships turn.

Ascending and Descending

An airship that is stationary, or traveling horizontally at 10 mph or less, may ascend up to 50 feet in a round. Airships traveling at 10 mph or less do not gain any horizontal movement while ascending, they remain in the same square while their altitude increases.

If a ship is moving horizontally at more than 10 mph, it may spend 150 feet of its forward movement to ascend up to 50 feet. Thus, a ship traveling at 200 feet per round (200 mph) may move forward 50 feet and ascend 50 feet (which costs it the additional 150 feet of its normal movement for the round). An airship traveling at 10 mph or less may descend up to 100 feet per round without danger.

An airship moving horizontally at more than 10 mph may descend up to 50 feet per 50 feet of horizontal distance covered during the round, at no additional movement cost. So, for example, an airship traveling at 250 ft. per round can descend 250 ft. during a given round without any horizontal
movement cost.

Faster ascents and descents are possible, but require specialized equipment and engines as well as a trained crew and captain. Knowing the limits of a vessel is an important part of flying an airship, those who attempt to force their craft into extreme maneuvers often pay the ultimate price (see ‘Pushing the Boundaries’ below).

Note that an airship that descends during a round may not then later ascend during the same round. In addition, a full round must pass between the descent of an airship and its ascent. Airships that ascend may then descend in the same round, however, provided they have enough movement to do so.

Turning

Each airship has a maneuverability rating, which determines the number of 45-degree turns it can make during a given round. An airship must move at least 50 feet (1 square) between each of these turns, though more extreme maneuvers may be possible (see ‘Pushing the Limits’, below) for particularly agile ships and skillful crews.

Due to the 50 foot minimum, ships with very high maneuverability ratings may not be able to take advantage of their accelerated turning rates when moving at slow speeds.

A ship with a maneuverability rating of 5, for example, need to travel at least 30 mph (250 feet per round) if it wishes to take all of its turns. Again, tighter turns can be made, as detailed below under ‘Pushing the Limits.’

Note that airships hovering at 0 mph may choose to take as many of their available turns as they wish in a single round, using the power of their engines to turn them in place rather than pushing them forward or lifting them up.

An airship can turn and ascend or descend during the same round-though an airship still may not descend and then ascend in the same or following round.

Acceleration

The max rate in MPH in which a vessel can accelerate in one round is equal to the power factors of its engines, minus its total tonnage, plus any modifications from special equipment (such as sails). Note that dirigibles serve to reduce an airship’s effective tonnage, even down to 0.

Acceleration is announced at the beginning of any round in which the captain wishes to increase the speed of his vessel. The captain must announce the amount by which he intends to increase his ship’s speed, up to the total amount of acceleration available. The airship moves at its current speed for the remainder of the round, but is considered to be moving at its new speed at the end of the round (barring an accident or other problem).

Accelerating at more than 20 mph is a dangerous tactic and all crew members that are not secured must make an Acrobatics check (DC 10 plus 1 for every 5 mph over 20) or be thrown to the deck. During combats this can be useful as an attempt to throw invaders off their feet, but it often has disastrous consequences.

Deceleration

A ship can decelerate a number of miles per hour equal to its current maneuverability times 10. Thus, a small ship with a maneuverability of 5 could decelerate 50 mph without any danger of losing control of the airship. If a pilot attempts a faster deceleration, he must immediately make a Piloting skill check (DC 17). If this check succeeds, the airship is able to decelerate by as much as 20 mph more than its maneuverability rating normally allows, but no more. If the check fails, the airship is immediately out of control (see below). Like with acceleration, deceleration of more than 20 mph per round requires the crew members to make Acrobatics checks.

Taking Off

When taking off from the ground, an airship must ascend at least 50 feet before it can begin any horizontal movement. At that point, it begins moving as per the rules stated above.

Landing

To land safely, a vessel must be moving at no more than 50 feet per round (5 mph) and cannot descend more than 50 feet during the round in which the landing occurs. More extreme conditions for landing cause damage to the vessel (and probably the crew, as well) and may cause the airship to ‘skip’ across the ground before finally coming to rest. A ship with a speed of zero can still move forward at a rate of 10 feet per round; such slow speeds are often used for docking maneuvers or other tricky flight operations that require a great deal of delicacy.

Facing

An airship’s facing is important to keep track of. An airship is always facing in a particular direction (as indicated on the counter or miniature used to represent the airship). This is important because the airship may have weapons on one side of the ship, but not the other, and to determine how far the airship can turn during a given round.

Pushing the Limits

For most captains, the basic information provided above is sufficient. They have no interest in pushing their ships into extreme aerobatic maneuvers and always land and take off using the approved speed limits. Others, such as pirates and warriors, prefer more aggressive maneuvers, pushing their airships to the very limits of their performance. While some ships are designed for this, most can handle the strain of these stunts for only a brief time before sustaining damage.

Abrupt Ascent

In times of emergency, it may be necessary to quickly elevate yourself above the fray. The abrupt ascent maneuver allows your vessel to rise up to its current forward movement rate (if it is not currently moving faster than 10 mph), but requires a Fortitude save (DC 10 + one-tenth the number of feet by which your vessel exceeds its safe ascent rate). If your vessel’s saving throw succeeds, it sustains no damage. If it fails, however, your ship suffers 1d6 hull points of damage. Airships that are traveling faster than 10 mph may use the abrupt ascent to rise 100 feet for every 150 feet of horizontal travel during the same round. This requires a Fortitude save (DC 10 + 5 for every 50 feet of ascent during the round beyond the safety limit) by the ship. If the airship fails its Fortitude save, it suffers 1d6 hit points of damage per additional 50 feet of ascent.

Plummeting Descent

By accelerating toward the earth, an airship can descend quite rapidly, though it may not be able to recover from its dive before impact with the earth. Regardless of its forward momentum, an airship may double the rate at which it can descend during a given round. However, it must descend one-half again the distance of its plummeting descent on the following round as it attempts to regain equilibrium and resume standard flight. A captain who wishes to reduce this secondary descent distance required after a plummeting descent forces his ship to make a Fortitude save (DC 10 + 1 per 10 feet by which the secondary descent is shortened). If the Fortitude save succeeds, the airship pulls out of its descent
without further difficulty and begins flying normally on the following round.

If this save fails, however, tremendous stress can crack the vessel right in half. The airship suffers 1d6 hull points of damage per 10 feet by which the dive was shortened. In addition, the vessel falls momentarily out of control and plummets an additional 1d10 x 5 feet before recovering and resuming normal flight.

Sharp Turns

In normal flight, an airship’s captain must allow for a full 50 feet of movement between each of its turns in a given round. It is possible, however, for a ship to make a sharper turn at the risk of overbalancing or straining the control mechanism. The captain of a ship may call for up to one-half of the ship’s available 45-degree turns to be made in any one normal turn interval. Doing so puts the ship at great risk of overbalancing, however, and even if the turn does not wreck the ship there is a good chance the steering mechanism suffers possibly fatal damage.
For every turn after the first which the ship makes without covering the required distance, the pilot must make a Piloting skill check (DC 15 + the number of turns made during this round, counting these). If this check succeeds, the airship must then make a Reflex save (DC 10 + the number of turns made during this round so far) or suffer a critical hit to the control mechanism (rudder, engine swivel, etc.). This critical hit is treated as if it had caused 1d6 points of damage per turn made during the round.
If the Piloting skill check fails, however, the airship immediately overbalances and begins rolling in the direction
of its last turn (see heeled over and rolling below).
Note that the airship’s speed is reduced by 5 mph for every additional turn it makes, as the engine’s force is used to turn the ship rather than applying forward momentum. Thus, a particularly sharp turn can bring even a very fast ship to a complete halt, as its engines struggle to compensate for the sudden change in direction. Ships must accelerate as normal after making a turn if the captain wishes to resume his cruising speed.
If an airship’s speed is reduced to less than 10 mph as a result of sharp turns, it also loses 50 feet of altitude and loses another 50 feet if the captain does not immediately accelerate during the following round.

Pushed Acceleration

By pushing the airship’s engine beyond its normal limits, it is possible to eke out a bit more acceleration. On the other hand, punishing the engine in so dramatic a fashion also carries the risk of blowing the engine apart and leaving the ship adrift. Pushing the acceleration of a ship always causes damage if there is not an engineer aboard the vessel and may cause such damage even if the airship’s crew does contain a qualified engineer.
When an engine is pushed, the captain must declare by how far he is willing to open the throttle. The ship may accelerate from zero to its maximum speed in a single round, but the Engineer must make a successful Profession (Airship Engineer) skill check (DC 15 + 1 per 5 mph of pushed acceleration) in order to keep the engine from damaging itself in the process. If this check succeeds, the acceleration is successful and the engine suffers no damage. If the skill check fails, however, the engine begins overheating and the stress of the acceleration starts tearing the machinery apart. In this case, the engine suffers 1d6 hit points of damage per 5 mph of pushed acceleration-this damage is applied at the end of the round in which the pushed acceleration occurs. Pushing a ship’s acceleration in subsequent rounds causes the ship’s engineer to suffer a cumulative -5 circumstance penalty on each of his Profession (Airship Engineer) skill checks.

If the airship does not have an engineer, the engine automatically suffers 1d6 hit points per 5 mph of pushed acceleration and cannot be pushed in two consecutive rounds. Any attempts to push the acceleration two rounds in a row without the assistance of an engineer immediately destroys the engine as if it had been reduced to zero hit points.
Dirigible ships without engines cannot push their acceleration in this fashion.

Mishaps in the Sky

There are many things that can happen to an airship as it flies along; unfortunately, most of them are simply not desirable, and may very well end with the ship broken and spiraling toward the earth. This section describes some of these mishaps and their results.

Heeled Over and Rolling

A ship that is caught by a strong wind, turns too tightly, or is rammed by another ship, may become
heeled over. This is air sailor slang for a ship that has tilted onto its side and is in danger of rolling over
completely. Sailors hate the idea of being heeled over, which is certain to end with a large number of sailors plummeting off the deck to their death on the hard ground below.

When a ship is heeled over, all crew members aboard must immediately make a Reflex save (DC 20) to grab hold of something before they begin sliding toward the ground. Any crew members who fail this Reflex save begin hurtling toward the ground, sliding across the deck and out into the air. Sailors below decks who fail this roll do not fall out of the ship, but may take falling damage depending upon how far they are from the nearest bulkhead. Even if no damage is taken, such men are knocked prone. Even worse, when a ship is heeled over, it is likely to continue its rotation, rolling completely over and pouring the last of its crewmembers over the side like so much unneeded ballast. To keep a ship from rotating over, the pilot must make a Profession (Sailor) skill check (DC 20) to use the engines to rotate the ship back into the correct position (that is, hull down, deck to the sky). If this skill check fails, then the vessel rolls over fully, with its deck facing the earth and its hull pointing toward the sky. At this point, any creatures or objects on the deck that were not previously tethered to the deck are dumped off the ship and crash to earth (using the standard falling rules) unless they are somehow able to fly or levitate on their own.

A ship that rolls begins losing altitude at the rate of 100 feet per round, starting on the round after it rolls over. The pilot must first right the ship before it can begin gaining altitude. Righting a ship requires a successful Profession (Airship Pilot) skill check (DC 25). If this skill check succeeds, the ship immediately rolls back over and the pilot may begin steering the ship, including ascending or descending, during the following round.

Crashing

Any time a vessel hits the earth or another terrain obstacle without making a landing, it has crashed. When a vessel crashes, it suffers 1d6 hull points for every 10 mph of its current speed, plus 1d6 hull
points of damage for every 50 feet of descent during the round in which it impacts the earth. Every creature aboard the ship when it crashes suffers the same number of hit points of damage as the vessel
suffers hull points. If a ship is reduced to fewer than zero hit points by a crash, it has broken up and all critical components suffer 2d6 hull points of damage as a result. In addition, all creatures on the ship suffer double the normal damage from the crash, as the shattered pieces of the ship explode through them like shrapnel.

Fires

Shipboard fires are a horrible tragedy if allowed to get out of hand. Any attack with an area of effect and which causes its damage primarily through heat or fire (such as any spell with the Fire descriptor or an attack from a Flame Projector) may set an airship alight.

If the damage comes from a spell, the airship must make a Fortitude save to avoid catching fire-this save has the same DC as the original spell DC and is in addition to any other save allowed to avoid damage. Damage caused by fire-based weapons forces a Fortitude save as well (DC equal to 10 + hull points of damage caused by the attack).

A successful save indicates that the ship is not set alight. A failed save, however, means the airship is burning, and it continues to burn until it is extinguished. The initial fire covers a 10’ square area at the center of the spell’s area of effect or wherever the physical attack landed. Each round, there is a 2 in 6 chance that the fire spreads to encompass another 10’ square. This new 10-foot square is chosen by rolling 1d8 and consulting Table 3.2. Roll for spread once a round per fire, not per 10’ square; fire always spreads from the most recently ignited square. If the fire spreads back into an area already on fire, it does no additional damage, but the fire has a 1 in 6 greater chance of spreading to additional squares during the next round. If a fire spreads past the edge of the deck, it begins moving down the side of the ship.

If the fire is on an exposed deck of the airship, increase the chance of it spreading each round by 1 in 6 for every 10 mph of the airship’s current speed above 30. If the airship is not moving, increase the chance of the fire spreading by 1 in 6 for every 20 mph of the wind’s current speed.
At the end of each round, every 10’ square that is burning causes 1d6 hull points of damage to the flaming airship. While airmen do not suffer damage unless they enter a burning square, they do suffer 2d6 hit points of damage during any round in which they perform an action within a burning square. A character who simply passes through a burning square can avoid the damage with a successful Reflex save (DC 10 + 1 per 5’ of flaming area the character has moved through during the round), but otherwise suffers the standard damage for the current square he is moving through. Note that fire causes one-half its normal damage to any components located in an engulfed area each round. Extinguishing a fire is not difficult, provided the fire has not spread. Every 10 ft. section of burning airship must be extinguished individually. Up to six fire fighters can work on each section, pouring sand or water on it. To automatically extinguish a 10. ft. section of burning airship, the crew must douse the flames with at least 30 gallons of water, or a similar amount of sand. The water or sand must all be applied during the same round. A single crewman is able to successfully apply 5 gallons of water or sand to the fire (distributing it evenly in an area, rather than just sloshing it down) as a standard action provided he has a sufficient quantity of water or sand (and a bucket to carry it) on hand. A
successful Wisdom check (DC 20) allows the crew member to apply up to 10 gallons of water or sand as a standard action, if this amount of extinguishing material is on hand.

If fewer than 30 gallons of water or sand are applied to the fire during a given round, the chance of extinguishing the fire drops to 50%. If fewer than 20 gallons of water are applied to the 10-foot section in the same round, the chance is a mere 25%, while fewer than 10 gallons of water applied in the same round simply cannot extinguish the fire at all. Fire-fighting materials are normally held below decks
unless a combat is imminent, in which case they are rolled into the center of the main deck, where they
can be readily accessed by the crew in the event of a fire.

Out of Control

An airship that is out of control is in grave danger. The pilot is no longer able to steer the vessel, leading to wild variations in facing, attitude, and altitude. Airships become out of control for a variety of reasons: poor weather conditions, severe damage, and over-aggressive piloting are just a few of the reasons an airship might find itself out of control. For the pilot, it’s not important to know what sent the airship out of control, what matters is getting the airship settled before it crashes.

At the end of every round that the ship is out of control, the pilot is allowed a single Profession (Sailor) skill check to regain control. The DC of this check is 15 plus 1 per 10 mph of the ship’s speed, and plus 2 for every altitude band the ship has gained or lost in the round. When an airship is out of control, a number of things happen during every round the out of control condition persists.

• Heading change. One per round, per point of maneuverability, the GM should roll 1d6. On a result of 1 or 2, the airship turns 45-degrees to its left. On a roll of 3 or 4, the airship does not change heading.
On a result of 5 or 6, the airship turns 45-degrees to its right. The changes should occur more or less at random, but no two turns occur within 50 feet of one another. An airship never turns directly into the wind when it is out of control. Treat any result which indicates an airship would make such a turn as if a 3 or 4 had been rolled.

• Speed Change. Fortunately for everyone aboard the airship, its speed begins decreasing the round immediately following the round in which it became out of control. The airship decelerates at a rate of 10 mph each round until the pilot regains control.

• Altitude Change. The GM should roll 1d6 at the beginning of any round during which the airship is out of control. On a result of 1 or 2, the airship descends 1d4 altitude bands. On a result of 3 to 5, the airship remains at its current altitude and, on a result of 6, the airship gains 1d2 altitude bands. Any airship which falls below the first altitude band while out of control crashes.

Aerial Movement

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